>>> good morning, america, on this thuday, april 8th. i'm robin roberts. >> and i'm bob woodruff. >> this morning, breaking news. the president signs a controversial arms control agreement with russia. george stephanopoulos is there in prague for the historic moment. >>> also breaking this morning, fighter jets scramble. air marshals jump into action, after an airline passenger claims he's lighting his shoes on fire. it was a false alarm. but what does it say about our security? >>> and as tiger makes his official return to golf today, nike releases a new ad that's raising eyebrows. >> i want to find out what your feelings are. and did you learn anything? >> yes. that is the voice of tiger's late father. is his comeback at a hit or a miss? >>> and the jon and kate debate. jon gosselin says kate's too busy dancing to raise the kids. we have her fiery rebuttal. >>> good morning, everyone. so happy to have bob woodruff here with us this morning. >> thanks for allowing me in. it's great to sit next to you. >> anytime. we know george is trave